Same thing happens to me (music starts fast-forwarding automatically and the ipod interface becomes somewhat unresponsive; the only "buttons" that work are the Next Track button ">|" and the Previous Track button "|<" ), and this only occurs when I use a 1/8 cable (Standard 3.5mm Stereo Cable) to connect the iPhone to any speaker system through an Aux 1/8 input (Car Stereo, LCD screen, Studio Mixer, etc.). It happens randomly and has occurred through all the firmware versions.
Note: It has never happened to me while I'm using the headphones, or while the iPhone it's docked on one of those iPod speakers (No cables needed, since the music is played through the device's dock). I have also tried using different 1/8 cables (6 different cables) hoping to solve it with no results.
This is the first thread on any forum that I have found, in which other users have the same (or at least quite similar problem), I hope Apple or someone else can help out (it's driving me nuts!!!).
Message was edited by: CarlosFerreiras